# 9 digits - sudoku variations — 4 brain teasing logic games > Four logic puzzle variations with thousands of puzzles and helpful hints. (iPhone/iPad app by Marcus Wagner.) - Source: https://appshunter.io/ios/app/9-digits-sudoku-variations/id432770625 (this page in markdown: same URL + `.md`) - Developer: [Marcus Wagner](https://appshunter.io/developer/359021564) - Category: Games, Entertainment, Puzzle, Trivia - Price: Free - Rating: 5.00/5 from 15 App Store ratings · 24 written reviews indexed - Age rating: 4+ - Requires: iOS 13.0 · 7 MB - Languages: American English, German (Germany) - Released: 2011-07-14 - Data updated: 2026-07-04 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/9-digits-sudoku-variations/id432770625/reviews.md ## What is 9 digits? Play 4 brain teasing logic games - Sudoku | Killer Sudoku | MathDoku | X-Sudoku - with thousands of puzzles. Don't get stuck - 9 digits' helpers guide your next move and teach you solution strategies. • choose levels from beginner to master • easily enter digits and pencil marks • get step-by-step hints for your next move • unique solutions, no guessing needed • plenty of settings to tweak your game experience • no ads 9 digits was created by Ivonne & Marcus who love to play logic games. ## Key features - Four logic game variations - Thousands of puzzles - Step-by-step hints - Solution strategy guides - Adjustable difficulty levels - Customizable game experience - Ad-free gameplay ## Recent user reviews (10 of 24) All indexed reviews: https://appshunter.io/ios/app/9-digits-sudoku-variations/id432770625/reviews.md ### 5/5 — Literally the best sudoku app on any platform *2020-06-30, version 1.4.0* Perfect. The interface is clean and easy to use. You are able to enter digits and pencil marks with a single swipe, as opposed to the keyboard method used by most other apps, which makes it far quicker to complete puzzles, and it makes the app easier to use with a single hand/thumb. There is a great variety of puzzles, as well as stat tracking, and the ability to customise your experience with features like automatic pencil mark removal, error checking, etc. However the biggest selling point of this app is the hint system. This app, unlike any other I have used, uses the hint system to not only help you with your current puzzle, but to teach you to get better at sudoku. There are so many techniques that I would never have known about if it weren't for the hint system in this app. It doesn't just give you the answer, it points out where you should focus, tells you what rule you need to apply, and then if you're still stuck, it tells you how and why to apply that rule. This has actually meant that 99% I no longer need to use hints. This system embodies the saying "give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime". ### 5/5 — Nearly perfect *2018-12-11, version 1.3.4* I play killer sudoku mostly, and out of many apps I've tried, I really like playing on this one. The clean interface is delightful to use. Number input is dreamy. The coloured and arrayed pencil marks are really helpful. The hints are a great feature: they are intelligent, the prompts leave you with some thinking to do if you like that, and the direct help means you don't get stuck. I'd like to be able to turn off automatic clearing of matching pencil marks when you enter a number. Help with valid number combinations for cages would be nice although I must admit that not having that forces me to think more. Help with adding cage sums would also be nice. Killer Sudoku + has a good rendition of both these features, and is another nice app, but it does not have arrayed pencil marks or the excellent hints that are given here. ### 5/5 — Genius interface *2018-07-02, version 1.3.4* The best user interface I have ever seen in a Sudoku game. The use of color and position to stimulate additional parts of the brain is a great plus ### 5/5 — Love this game! *2018-05-05, version 1.3.4* I love love love puzzles and I've never found another game that's so thoroughly challenging and logical in nature. It's a shame it isn't more popular! ### 5/5 — Already love it *2016-02-20, version 1.3.4* Looks much more fun and colorful than most sudoku apps and has a good selection of games and an intuitive pencil mark interface ### 5/5 — Add support for iPad please! *2016-01-08, version 1.3.4* Nice app otherwise. ### 5/5 — Best Sudoku App, by far *2015-10-17, version 1.3.4* This is a real tool for players that are serious about Sudoku. There are many many puzzles at many skill levels. The amazing, amazing hint system actually teaches you how to play better. The app is super smooth and responsive at all times. No competition. ### 5/5 — Excellent sudoku *2015-01-05, version 1.3.2* Took a bit to get used to putting numbers in cells. Very much worth it. Great sudoku game. My favorite ### 5/5 — Awesome! *2013-10-11, version 1.2.1* I love this app. It is well organized, easy to use and extremely addicting ### 5/5 — Great!! *2013-05-06, version 1.2.1* Best sudoku app I've used so far! Tons of puzzles, great variations, and the hints really help you improve your skill!! ## Frequently asked questions about 9 digits ### What logic games are included in 9 digits? 9 digits includes four brain-teasing logic games: Sudoku, Killer Sudoku, MathDoku, and X-Sudoku. Each game offers thousands of unique puzzles to solve. ### Does 9 digits offer hints or assistance for puzzles? Yes, 9 digits provides step-by-step hints to guide your next move and teach solution strategies. This helps players learn and improve their puzzle-solving skills without needing to guess. ### Can I adjust the difficulty in 9 digits? Absolutely. 9 digits allows you to choose levels ranging from beginner to master. This ensures the game is enjoyable and challenging for players of all experience levels. ### Is 9 digits available on multiple devices? Yes, 9 digits is available on iPhone, iPad, and iPod. It is designed to provide a seamless logic puzzle experience across these Apple devices. ### Does 9 digits have ads or in-app purchases? No, 9 digits offers a completely ad-free experience and does not have any in-app purchases. The game is free to download and play. ### How often is 9 digits updated? The latest version of 9 digits is 1.4.1, last updated on June 13, 2021. While updates are not frequent, the existing content provides thousands of puzzles. ### What is the age rating for 9 digits? 9 digits has an age rating of 4+. This makes it suitable for a wide range of players, including younger individuals interested in logic puzzles. ### What makes 9 digits unique compared to other Sudoku apps? 9 digits stands out by offering four distinct logic puzzle variations beyond standard Sudoku, along with integrated strategy guides and a completely ad-free, free-to-play model. ## Version history (last 5 releases) ### 1.4.1 — 2021-06-13 • iPad portrait shows larger puzzle • Setting “Colored Digits” is retained during gaming ### 1.4.0 — 2019-10-14 • iPad support • new setting: no automation for removing obsolete pencil marks ### 1.3.4 — 2015-09-03 • new setting: “Sudoku and X-Sudoku start with prefilled pencil marks” • new: set and restore a game savepoint • fixed Killer Sudoku puzzle 50, professional in Classic Pro Pack 6 ### 1.3.3 — 2015-07-11 • new setting: “Show a row of digits which still need to be assigned” • updated for iPhone 6 and 64-bit ### 1.3.2 — 2014-05-14 • “autofill cells with single pencil marks” optimized for Killer Sudokus and MathDokus (Check the preferences) • removed any prompts to rate 9 digits ## Apps similar to 9 digits | App | Rating | Price | Category | | --- | --- | --- | --- | | [Killer Sudoku - Daily Sudoku](https://appshunter.io/ios/app/killer-sudoku-daily-sudoku/id6736829438) | — | Free | Games | | [Killer Sudoku Master-SumSudoku](https://appshunter.io/ios/app/killer-sudoku-master-sumsudoku/id6464051208) | 4.5 (10) | Free | Games | | [Sudoku Game - Number Puzzle](https://appshunter.io/ios/app/sudoku-game-number-puzzle/id1166550577) | 5.0 (1) | Free | Games | | [Fast Sudoku Basic Puzzles](https://appshunter.io/ios/app/fast-sudoku-basic-puzzles/id6451101501) | — | Free | Games | | [Sudoku Unlimited Puzzles](https://appshunter.io/ios/app/sudoku-unlimited-puzzles/id807117894) | — | Free | Games | | [Sudoku - math puzzle game](https://appshunter.io/ios/app/sudoku-math-puzzle-game/id1060524559) | 4.6 (5) | Free | Games | ## More apps by Marcus Wagner - [It's on my list](https://appshunter.io/ios/app/its-on-my-list/id359021561) All apps by Marcus Wagner: https://appshunter.io/developer/359021564 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-04.*